I have been having my what great-grandma Maudie would call "a time" with my computer. It turns out that those random, continual restarts it kept insisting on, for months, were its shy, understated, El Capitan way of performing a kernel panic. Like, it was constantly kernel panicking. Ten times a day, sometimes, and because I hadn't been reading the Apple Support site for fun since OS X became "macOS," I had no idea. By the time I figured it out, the System had become Corrupted. So I started backing things up, but during that process I discovered that my elderly FireWire drive was, in some subtle way, completely (as Great-grandma Maudie would say) borked, and had been quietly eating all the files I sent it. So, I had to go buy a new one (mine is silver). I slapped my entire user folder onto the new drive without enquiring further, and I made a bootable Sierra volume, thinking I would do a clean install and save myself a lot of grief trying to figure out what exactly had been fucking with my old system. That was when I started really having fun. First, I couldn't get the iMac's built-in HD to erase. Disk Utility said it was too full to work on (?), it wasn't a hard disk, it wasn't writable, whatever. I had to zero it out completely, twice, which took days. Then, there was something wrong with the copy of Sierra on the boot volume (still don't know what), and because my HD had been wiped I couldn't get in to download it again. I finally managed to borrow an old Macbook, redownload Sierra, and make a new boot volume (a week), but because the Macbook was so old it had limited available real-estate, so Sierra had just put the installer in the boot drive, to save space. So then I had to wait while the boot drive downloaded Sierra onto my computer (two days) before actually installing it. I ended up finally getting Sierra installed, and my electricity went out for three days. I was feeling really cheerful and relaxed at this point, as you might imagine, so when the time came to turn my iMac back on I was happy as a fucking clam to find myself continually rejecting the advances of Siri, a completely useless product feature Apple has decided to saddle their new desktopOS with for reasons that remain opaque to much of the marketplace. I would like to point out, here, that despite what you may have seen in various creatively-lit Apple commercials, Siri is completely useless for any purpose besides LARPing Star Trek: The Next Generation. Siri is also, even now, trying to turn herself on all the goddamn time, even though I keep telling her no. Siri is a PUA.
Anyway! After doing all the annoying set-up that any system would require, and requesting a PFA on Siri, Sierra asked me if I would like to host all my files and my desktop environment on iCloud (this would require me to pay money to Apple every month for the privilege), and I said HAHANO, but I allowed as how putting my iBooks library and my Notes and Mail and some other shit on there would be a good idea — and we are approaching Part Two of the narrative now, if you'd like to get up to refresh your beverage — and I sat still for hours playing mah-jongg while Sierra transferred files. Aaaaaaaaaand! And! Can you guess what happened next, Reader? iCloud destroyed my system. It fucked up every aspect of Safari, intermingled my bookmarks/Reading List with shit from my mom's c.2004 iTunes account (I don't even know how!), and destroyed by iBook library. And when I say "destroyed," I mean "first it refused to put the ebooks on my iPad, then it ate them and they disappeared, except for the ones I'd bought in the iBooks Store." We're talking about hundreds of books, here. We're talking about notes on hundreds of books. We're talking about my painfully close reading of Jonathan Strange & Mr Norrell. I spent another entire week trying to fix iBooks (none of the Apple Support solutions worked), before finally giving up, getting my old iBooks library out of my backed-up user folder, and turning iCloud off forever. I also retired Safari rather than waste further hours of my dwindling lifespan trying to figure out what happened to it and how to stop it from continuing to happen/happening again. I'm now using Chrome (business) and Firefox (party), and I sync my iBooks manually, just like it says to do in the Bible. After I got through all that, though, I began to have lots of peculiar, random click problems that basically made my freshly-waxed computer unusable, but I eventually figured out that my legacy Wacom drivers (I used a Bamboo tablet as a mouse) were causing system-wide instability. So I uninstalled every part of the driver architecture, got out the Magic Mouse that shipped with my iMac, and discovered that... it no longer worked. Cleaned it out with a can of air and a microfiber cloth, changed the batteries: nothing. So I conscientiously, despairingly navigated to Apple's website using a pink Hello Kitty mouse borrowed from my niece, and discovered that everyone hates the new Apple Magic Mouse because it has sharp edges that you can cut yourself on and you have to flip it over to charge it. So I bought a "like new" used old one, and it works fine and arrived, indeed, in out-of-the-box condition. (One.)